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SAY HELLO TO HELMINTHS!
HELMINTHS
• Multicellular invertebrate worms; typically macroscopic as adults; may
be parasitic/infectious or neutral heterotrophs found in soil and water
of virtually all environments
• Contaminate food, water, air, feces, pets, wild animals, and various
surfaces
• Prevention:
• Frequent hand washing
• Frequent cleaning of bathrooms and kitchens
• Thorough cooking of beef, pork, sausage, and game meat
COMMON HELMINTHS
• Roundworms aka Nematodes • - about 1 million species
• Parasitic nematodes hatch/live in intestines
• Symptoms
• fatigue
• Weight loss
• Irritability
• Poor appetite
• Abdominal pain
• Diarrhea
• Untreated
• Anemia
• malnutrition
COMMON HELMINTHS IN MEAT
• Trichina spiralis (trichinosis)
• Ingested via undercooked pork, sausage, or game meat – especially bear
meat (responsible for 1/3 of the 100,000 cases of trichinosis in the US per
year)
• Spread throughout bloodstream and lymphatic system
• Symptoms of infection
• First stage – Vomiting, diarrhea, muscle cramps, fever, sweating
• Untreated – Second stage
• Penetration of muscles, heart, and brain – intense muscle and joint
pain, shortness of breath
• Symptoms usually subside, but there is no cure for the infection once
the larvae are encysted in muscles and may lead to death
• Tapeworms (cestodes)
• Ingested via undercooked
beef or sometimes raw pork
• Live in intestines – up to 25 M
long – absorbs nutrients
through its body
• Symptoms
• Usually absent
• May include abdominal
pain, fatigue, weight loss,
diarrhea
COMMON HELMINTHS
PINWORMS
• AKA: seatworms or threadworms
• Most common worm infection in the US
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Ingested in contaminated food or drink, or by hand – self inoculation is common
Embryonated eggs are on clothes, bedding, bathroom fixtures or dust
42 million people infected globally
Mostly children aged 5-14 years
Commonly institutional settings such as child care facilities, hospitals, or family
members
• Only helminthic infection with approved OTC treatment
• Symptoms – itching, sleep disruption, sometimes nausea, abdominal pain and
diarrhea
PINWORM LIFECYCLE
1. Adult males and females inhabit
ileocecum.
2. Female migrates out of anus and
deposits eggs in perianal region then
dies.
3. Eggs hatch within a few hours and
larvae return to large intestine via anus
(retroinfection), crawl into genitourinary
tract, or eggs are reingested by the
host.